1. Field of the Invention
The present invention relates to an iris imaging apparatus used as a security system, particularly, realizing the reduction in size and in costs.
2. Description of the Related Art
In security systems, a method is known that the iris pattern of individuals is used for authentication. The authentication method using the iris has an advantage that the iris image of a person to be authenticated is imaged by a camera from a remote place without contacting the iris different from fingerprints, which is expected to become popular in future.
An iris imaging apparatus for imaging the iris image needs to capture the iris image of the person to be authenticated at high speed as a sharp image, thus having various drive mechanisms. For example, it needs to image the image of the person to be authenticated by a wide angle camera, to calculate the position of the eye of the person to be authenticated from the image imaged by the wide angle camera, and to set the orientation of a telephoto camera to the position of the eye highly accurately. Therefore, a pan mechanism and a tilt mechanism are disposed in the telephoto camera. In addition, the iris image becomes sharp when it is imaged with the use of near-infrared radiation. Thus, a lighting device for emitting near-infrared radiation is mounted on the iris imaging apparatus, and the lighting device also has the pan mechanism and the tilt mechanism so as to be directed to the position of the eye of the person to be authenticated.
As described above, the iris imaging apparatus of the related art needs to mount many drive mechanisms, which has a problem to cause the obstacles to compactness and low costs.
The object of the invention is to provide an iris imaging apparatus which is compact at low cost by solving the problem.
To achieve the above object, the invention provides an iris imaging apparatus of the invention comprises a telephoto camera for imaging an enlarged image of an eye of a person to be authenticated, an iris lighting device controlled to emit light when the telephoto camera images the enlarged image, a iris lighting motor for rotating the first iris lighting device to set direction of the iris lighting device to a position of the eye of the person to be authenticated, a platform, and a turning stage rotatablly mounted on the platform, with which the telephoto camera, the first iris lighting device and the iris lighting motor are mounted.
With the configuration, the apparatus can be formed compact at low cost.
Preferably, the iris imaging apparatus further comprises a wide angle camera for imaging an image to determine the position of the eye of the person to be authenticated and a wide angle camera lighting device controlled to emit light when the wide angle camera images, wherein the wide angle camera and the wide angle camera lighting device are mounted with the turning stage. Therefore, the position of the eye of the person to be authenticated can be calculated highly accurately from the image imaged by the wide angle camera to capture the iris image suitable for the iris authentication.
Preferably, the iris imaging apparatus further comprises a controller for controlling the wide angle camera lighting device to emit light and controlling the telephoto camera to image the iris image of the person to be authenticated when an image of the first iris lighting device is reflected in an iris image of the person to be authenticated imaged by the telephoto camera. Therefore, an good iris image can be imaged even when the first iris lighting device cannot be used.
Preferably, a rotation axis of a turn motor for turning the turning stage is set to the turning stage. As all the main components of the iris imaging apparatus are set to the turning stage, electrical wiring on the turning stage can be facilitated.
Preferably, the iris imaging apparatus further comprises a rotating mirror for reflecting an incident light from the eye of the person to be authenticated to the telephoto camera, and a rotating mirror motor for rotating the rotating mirror, wherein the rotating mirror and the rotating mirror motor are mounted with the turning stage, and the telephoto camera is disposed transversely so that the rotation axis of the turning stage is coaxial with an optical axis of the telephoto camera. Therefore, the force required to turn the turning stage is small, and a small motor can turn it.
Preferably, a range sensor for measuring distance to the person to be authenticated is provided to a position below the rotating mirror. Therefore, the distance to the person to be authenticated can be measured accurately to focus the person to be authenticated at higher speed.
Preferably, the range sensor is provided so as to rotate in one piece with the rotating mirror. Therefore, the distance to the person to be authenticated can be measured at low cost.
Preferably, a substrate having a unit for controlling a subject to be electrically controlled is mounted on the turning stage. Therefore, all the subjects to be electrically controlled on the turning stage can be controlled on the turning stage, the electrical wiring for the control system is further facilitated, and the wiring lines are prevented from hindering turning the turning stage.
Preferably, the iris imaging apparatus further comprises a second iris lighting device controlled to emit light when the telephoto camera images the enlarged image, a first position where the first iris lighting device is provided is left side of the turning stage and a second position where the second iris lighting device is provided is right side of the turning stage, and the first position and the second position are asymmetric with respect to an optical axis of the telephoto camera directed to the person to be authenticated. Therefore, the image of the first iris lighting device or the second iris lighting device is prevented from being reflected in the iris image to heighten the probability that an good iris image can be captured. In addition, the number of light emitting diodes used for the first lighting device and the second lighting device can be reduced, which realizes further cost reduction.
To achieve the above object, the invention provides an iris imaging apparatus comprises a platform, a wide angle camera for imaging an image of a person to be authenticated, a wide angle camera lighting device controlled to emit light when the wide angle camera images, a telephoto camera for imaging an enlarged image of an eye of the person to be authenticated, an iris lighting device controlled to emit light when the telephoto camera images the enlarged image, a first motor for rotating the iris lighting device direct luminous light in a direction of the person to be authenticated, a turning stage rotatablly mounted on the platform, with which the wide angle camera, the wide angle camera lighting device, the telephoto camera, the iris lighting device and the first motor are mounted, and a second motor for turning the turning stage. As motor for turning the components mounted on the turning stage in the turning direction can be shared, the number of motors can be reduced. Therefore, the apparatus can be formed compact at low cost.
Preferably, the wide angle camera lighting device and the iris lighting device are arranged side by side adjusted lighting direction by the first motor. According to the configuration, the person to be authenticated can be illuminated efficiently by the wide angle camera lighting device. Therefore, the number of the light emitting diodes use for the wide angle camera lighting device can be reduced.
Preferably, the iris imaging apparatus comprises a controller for controlling the second motor, and the wide angle camera, the wide angle camera lighting device, the telephoto camera, the iris lighting device and the first motor mounted on the turning stage, wherein the controller is mounted with the turning stage. As all the electrical wiring lines routed to the separate components on the turning stage from the controller can be routed on the turning stage, the wiring lines can be prevented from hindering the turning operation of the turning stage.